Exterior shell of a truck grill crown



FIG. 1 is a top perspective view of an exterior shell of a truck grill crown showing our new design, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a top perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a side elevation view of one side thereof, the opposite side being a mirror-image of the one side; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for an exterior shell of a truck grill crown, as shown and described. 